In order to follow-up a linkage finding on chromosome 11p15.5 to alcohol dependence (Long et al., submitted), two short tandem-repeat marker panels for semi-automated fluorescent genotyping containing 15 loci distributed over the distal 20 cM of chromosome 11p15.5 have been created. One panel (six loci) has been typed in approximately 500 psychiatrically-interviewed individuals from a Southwest American Indian tribe. A second panel (nine loci) has been optimized and typing will begin soon. In addition, two coding polymorphisms and one promoter polymorphism at DRD4, a candidate gene for involvement in vulnerability to alcohol dependence, have been typed in order to develop haplotypes at this locus, distal to the short-tandem repeat locus linked in the whole genome linkage scan. Haplotype construction, sib-pair linkage analysis and map construction will be performed to confirm the primary linkage finding and define intervals of maximum linkage to alcohol dependence.